When I did my elaborate A/B comparison AKM vs. ESS chips (ADI-2 Pro vs ADI-2/4) I first found exactly that:
AKM sounded somewhat smoother (you can call it velvet if you like).
https://forum.rme-audio.de/viewtopic.ph … 60#p195160
Checking closer and doing a little measurement I found that my selected DA filters, also carrying the same name, are different shaped in both both chips.
The AKM’s have a softer transition into the stop-band on most, but not all filters.
This, by the way, is even visible in the diagrams in each unit’s user’s manual.
When I choose similar shaped filters the difference completely disappeared.
If you compare you always have to be very careful to compare apples to apples, and exclude expectation bias.
The Internet is really lousy in this regard, almost nobody cares.
Myths built up faster than you can say: “booh”.
Nevertheless, the old AKM’s have a very slight edge in the features:
Bronx on - they have f****g DSD-direct to handle the f****g DSD format - Bronx off –
but RME did a good job working around that with ESS.
Anyway, I like my ESS ADI-2/4 Pro SE.